20726947 has 4 divisors (see below), whose sum is σ = 20842920. Its totient is φ = 20610976.

The previous prime is 20726939. The next prime is 20726971. The reversal of 20726947 is 74962702.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20726947 - 2³ = 20726939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20726047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57718 + ... + 58075.

It is an arithmetic number, because the mean of its divisors is an integer number (5210730).

Almost surely, 2^20726947 is an apocalyptic number.

20726947 is a deficient number, since it is larger than the sum of its proper divisors (115973).

20726947 is a wasteful number, since it uses less digits than its factorization.

20726947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115972.

The product of its (nonzero) digits is 42336, while the sum is 37.

The square root of 20726947 is about 4552.6856908862. The cubic root of 20726947 is about 274.6914313049.

The spelling of 20726947 in words is "twenty million, seven hundred twenty-six thousand, nine hundred forty-seven".